Studies of the TSH and exophthalmogenic factor receptor in thyroid and retro-orbital tissues will be continued. Receptor differentiation in tissue cultures of thyroid cells will also be studied. The mechanism of procollagen peptidase, including its secretion from cells, and the mechanism of active enzyme formation will be studied. Studies on the biosynthesis of type I procollagen and type III procollagen will continue. Studies of D-lactate dehydrogenase structure-function and its ability to reconstitute bacterial transport will be continued.